Comments to date on reaffirmation of AES-3id-2001 AES information document for digital audio engineering - Transmission of AES3 formatted data by unbalanced coaxial cable, published 2006-07-08 for comment.
I have a few commnents:
The AES-3id-2001 document refers to the AES3-1992. I am assumimg that the new AES-3id will refer to the new AES3-2003 document.
The new AES3-2003 includes the possibility to carry digital data sampled at up to 192 kHz. This means that several sections of the AES-3id-2001 document will need to be updated to reflect the fact that the new bit rate can be up to 24.5 Mbps, which means a fundamental at 12.2 MHz. Sections describing the impedance should specify a return loss of 15 db minimum from 0.1 MHz to 24 MHz. In addition, the section about the equalizer characteristics will need to be updated.
Standards Compliance Manager
Leitch Technology International
Harris Broadcast Communications Division
In answer to your very relevant comments on the reaffirmation of AES-3id, I have prepared the following response, which I hope you will find satisfactory.
AES-3id is offered for reaffirmation, allowing for no revision of substantive content and only editorial correction. However, it will be possible to add a note to the scope to address this issue as follows:
" Note to 2006 edition: This document was written tin the context of basic-rate sampling frequencies (see AES5-2003). No provision is made in this document to handle signals carrying stereo audio at double and quadruple sampling frequencies. It should be possible to expand the parameters quoted to handle such signals using common-place engineering techniques, and much modern video equipment will handle such signals in coaxial form. "It has been proposed to incorporate AES-3id into AES3 in a future revision of that standard so that balanced and coaxial transmission are treated equally. The issue of bandwidths and other parameters will be addressed fully in such a revision.
Yours, Robin Caine, chair of SC-02 and co-author of the original AES-3id.